Field of the Invention
The present invention relates to a process for producing a substrate having wiring, a radiation-sensitive composition, an electronic circuit and an electronic device.
Discussion of the Background
For electronic devices including liquid crystal displays, mobile information devices such as mobile phones and tablets, digital cameras, organic EL displays, organic EL lights and sensors, there has been demand for their downsizing and thinning and providing them with higher performance. Processes for more inexpensively producing those electronic devices that have been attracting attention are printed electronics in which wiring is directly printed. The printing processes for the production of electronic parts can usually skip multi-stage steps including exposing and developing and a vacuum step such as vapor deposition, and therefore are expected to significantly simplify processes.
The printing processes, such as inkjet printing, screen printing, gravure printing and gravure offset printing, enable wiring with a desired pattern to be directly formed on a substrate, and thus are employed as simplified processes incurring lower cost. Yet, the formation of the wiring with a desired pattern involves the wiring-forming materials flowing leading to wet-spreading and bleeding. Thus, conventional art has faced limitation for the formation of fine patterns excellent in linearity.
Meanwhile, in the use of wiring-forming materials for patterning by printing, it has been actively studied to form the metal wiring by thermal calcination or photo calcination (for example, see JP-A-2011-241309). This technique still cannot overcome the wet-spreading and bleeding of the material at the time of printing and is inadequate in the adhesion between the resultant wiring and the substrate.
In order to solve the above problems and thereby enable high-definition printing and to form a high-definition wiring, it has been studied to provide a layer serving as foundation (foundation layer) for the wiring. The foundation treatment for the provision of the foundation layer is often performed for the purpose of inhibiting the wiring-forming material applied on the substrate from wet-spreading, bleeding or the like and thereby improving printability.
The foundation treatment methods that are known include a method in which the grafting of an epoxy group is performed with respect to a substrate (for example, see JP-A-2003-114525 and JP-A-2006-58797); a method in which a photocatalyst is applied on a substrate (for example, see JP-A-2003-209340 and JP-A-2004-98351); and a method in which an acrylic copolymer is applied on a substrate (for example, see JP-A-2012-232434 and JP-A-2012-218318).
However, the conventional foundation treatments for the provision of the foundation layer is insufficient in inhibiting the wiring-forming material from wet-spreading and bleeding, and therefore the formation of a high-definition wiring has been difficult. For example, under the conventional foundation treatments, properties of surfaces of the foundation layer on which the wiring-forming material is applied are uniform, and thus it is unsuccessful to sufficiently inhibit the wiring-forming material printed with a prescribed pattern from wet-spreading immediately after its printing.